1. Field of the Invention
The present invention relates to gynecological balloons.
2. Description of the Related Art
Endometrial carcinoma, a malignant adenocarcinoma of the glandular epithelium lining the inner wall of the uterus, is one of the most common and serious disorders affecting the endometrium of post-menopausal women. Endometrial carcinomas represent an increasingly frequent tumor occurrence in industrialized countries. For example, in 1997, an estimated 170,000 new cases of endometrial carcinoma were diagnosed worldwide. The high occurrence of this malignancy necessitates the development of new therapeutic treatment alternatives. Moreover, early eradication of the carcinoma generally results in a more favorable prognosis for the patient. While surgical removal of the tumor is a preferred method of treatment, there may be some situations when a patient is unable to tolerate surgery. In some situations, a physician may prescribe one or more courses of preoperative radiation therapy. In yet further situations, surgery may be contraindicated or, particularly in the case of early stage carcinoma, even unnecessary. Additionally, it may be advisable for a patient who has undergone surgery to remove the tumor to undergo one or more courses of radiation therapy to eradicate any remaining tumor cells that may not have been excised.
Radiation therapy is used extensively to treat endometrial malignancies, either pre-operatively, as adjuvant therapy after surgery for patients with greater than stage IA disease, as primary therapy for patients unable to tolerate surgery, or to treat recurrences following surgery. Radiation therapy has been used for uterine cancers for over a century, and may be administered as either external beam treatment, brachytherapy, or both. In some cases, curative intracavitary brachytherapy may represent the most desirable treatment option. Curative intracavitary brachytherapy is frequently used to treat malignancies of the vagina, cervix, and endometrium (the lining of the uterus or vagina). Treatment of the endometrium by intracavitary brachytherapy may be referred to herein as intrauterine brachytherapy. While early stage tumors are more responsive to intracavitary implants, more extensive tumors may require treatment with interstitial implants and may involve a combination of external beam radiation therapy and intracavitary and/or interstitial brachytherapy.
Brachytherapy may also be described according to the length of time that a procedure is performed. Low dose rate (LDR) treatments typically require several days if the radioactive sources are temporarily placed in tissue. In some cases, permanent or semi-permanent implants may be preferred, wherein the materials remain in the tissue for a substantial portion of time. During most LDR brachytherapy procedures, a dose of radiation in the range of about 0.4-0.8 Gy/hr is administered. High dose rate (HDR) brachytherapy typically uses high specific activity gamma-emitting radionuclides to deliver a much greater dose (usually >0.4 Gy/min) of radiation to the site than what is administered using LDR brachytherapy. As such, HDR brachytherapy procedures are shorter in duration, and usually last less than an hour. HDR brachytherapy allows precise delivery of the radiation dose prescribed by the physician. The short treatment times, the amenability to performing HDR procedures on an outpatient basis, and accurate radiation delivery and improved patient comfort and compliance are all advantages of HDR brachytherapy.
A common gynecological applicator used for brachytherapy is often referred to as a tandem and ovoid set. The applicator usually comprises a curved tandem and a set of ovoids, each of which are at the end of control arms. The Utrecht Interstitial Fletcher Applicator supplied by Nucletron BV of The Netherlands is a tandem and ovoid set. Various patents have issued that concern advances in the typical cervical applicator. For example, U.S. Pat. No. 4,434,789, issued on Mar. 6, 1984 to Kumar, describes an apparatus for treating carcinoma of the uterine cervix by judiciously applying radioactive material immediately adjacent the uterine cervix for an extended period of time empirically determined by the radiologist. The applicator has three radioactively chargeable components including a central tubular tandem vaginally insertable into the cervix and two non-lineal tubular ovoids locatable at the cervix and positioned laterally between the respective vaginal walls and the uterine cervix. The ovoidal assemblies are removably and pivotably connected to the central tandem component.
Another common gynecological applicator used for brachytherapy is often referred to as a tandem and ring set. The applicator usually comprises a curved tandem and an interstitial ring, each of which are at the end of control arms. The Interstitial Ring Applicator supplied by Nucletron BV of The Netherlands is a tandem and ring set. A tandem and ring applicator has two radioactively chargeable components including a central tubular tandem vaginally insertable into the cervix and an interstitial ring locatable at the cervix and positioned laterally between the respective vaginal walls and the uterine cervix.
During the use of radiation therapy, it is important to direct the radiation dose to the targeted area while minimizing radiation received by other areas, such as the rectum and bladder. In the present situation, it is important to minimize the dosage received by the bladder and the rectal wall. Various patents and patent publications use shields to prevent complications due to misapplied radiation. U.S. Pat. No. 7,556,596, issued on Jul. 7, 2009 to Mourtada et al., proposes an adaptive brachytherapy applicator with remotely-controlled radial and longitudinal motion radioactive source lumen shields that can be manipulated by the radiation oncologist to optimize the dose distribution to the target and normal tissue structures for brachytherapy procedures.
U.S. Pat. No. 5,012,357, issued on Apr. 30, 1991 to Schoeppel et al., proposes a system with an applicator arrangement which has a pair of colpostats in conjunction with a tandem. The colpostats and tandem are formed of a material which is transparent to an imaging modality, such as CT scanning. Imaging-transparent source carriers containing dummy, or test, sources are placed in the colpostats. After the location of the colpostats, for example, has been determined, by imaging, the dummy source carriers are removed therefrom and replaced with selected source carriers containing actual radiation sources. The radiation source carriers further contain shielding which controls the strength and radiation pattern of the emitted radiation, all of which may be selected in response to the image. The dummy source carriers are provided with markings thereon, which are opaque to imaging, so that the position and orientation of the source carriers with respect to the tissue region to be irradiated can be determined from the images.
U.S. Pat. No. 5,947,891, issued on Sep. 7, 1999 to Morrison, proposes an instrument for treating vaginal malignancies which a tubular applicator, a separable vaginal retainer and an interlocking structure between the two. The tandem is adapted to receive a linear tube containing multiple sources of radiant energy and terminates at its inner end in a curved intrauterine portion. Two halves of the separable retainer surround the tandem and cooperatively form a vaginal cylinder for occupying the vaginal vault and a handle. The interlocking structure includes outwardly extending projections and cavities in the handle so positioned that the structure is visible to the physician at all times.
As discussed above, a very important consideration when treating patients using radiation therapy is that the proper dose of radiation reaches the treatment site. This is important whether the treatment method utilizes implanted radiation seeds, HDR, or external beams of radiation. Excessive dosing of the patient can lead to severe side effects including urinary incontinence and rectal bleeding issues. A proper treatment plan should deliver an adequate amount of radiation to the treatment site while minimizing the dose delivered to the surrounding tissues or organs at risk.
U.S. Pat. No. 6,963,771, issued on Nov. 8, 2005 to Scarantino et al., proposes a method, system and implantable device for radiation dose verification. The method includes (a) placing at least one wireless implantable sensor in a first subject at a target location; (b) administering a first dose of radiation therapy into the first subject; (c) obtaining radiation data from the at least one wireless implantable sensor; and (d) calculating a radiation dose amount received by the first subject at the target location based on the radiation data obtained from the at least one wireless sensor during and/or after exposure to the first administered dose of radiation to determine and/or verify a dose amount of radiation delivered to the target location.
U.S. Pat. No. 7,361,134, issued on Apr. 22, 2008 to Rozenfeld et al., proposes a method of determining the dose rate of a radiation source including locating three or more detectors in the vicinity of a source. Each of the detectors provides an output indicative of the amount of radiation received from the source and determines the location of the source from at least some of the detector outputs. International Pub. No. WO 2008/148150, published on Dec. 11, 2008 to Rozenfeld, proposes a semiconductor radiation sensor.
U.S. Patent Publication No. 2009/0236510, published on Sep. 24, 2009 to Lacroix et al., proposes a radiation dosimeter for measuring a relative dose of a predetermined radiation type within a detection region by using a plurality of scintillating optical fibers. U.S. Patent Publication No. 2006/0094923, published on May 4, 2006 to Mate, proposes a marker comprising a wireless transponder configured to wirelessly transmit a location signal in response to a wirelessly transmitted excitation energy.
During use of a traditional applicator, a treating professional must secure the device within the vaginal cavity. This is usually done by packing the cavity with gauze strips, which can be both time consuming, unreliable, and uncomfortable to the patient even to the point anesthesia may be administered. Various patents have issued which attempt to avoid this step and improve the process. For example, U.S. Pat. No. 4,554,909, issued on Nov. 26, 1985 to Pino y Torres, proposes a therapeutic instrument and method for radiation treatment of patients with carcinoma of the cervix and uterus. An elongated uterovaginal tandem having a curved proximal end is inserted in the uterine cavity, and an intravaginal applicator having a bore receiving the tandem is slid over the tandem into the vagina, and the tandem and applicator are fixed so that no relative motion therebetween is possible. The applicator obviates the need for packing of the vagina, having a quadrate cross-section, with rounded corners that substantially fills the vagina if the appropriate size of applicator is selected. Sutures are used to connect the distal end of the applicator adjacent the vaginal introitus. The applicator is then loaded with a pair of containers of irradiative material. The containers are inserted utilizing handles through passageways in the applicator to cavities in the applicator on either side of the tandem and adjacent the slanted proximal end of the applicator. The tandem is located with respect to the applicator cavities so that a greater distance is provided between the irradiative material containers and the vaginorectal septum.
The above discussed U.S. Pat. Nos. 4,434,789; 4,554,909; 5,012,357; 5,947,891; 6,963,771; 7,361,134; and 7,556,596; and Pub. Nos. U.S. 2006/0094923 and 2009/0236510; and International Pub No. WO 2008/148150 are hereby incorporated by reference for all purposes in their entirety.
A need exists for a gynecological apparatus to immobilize and displace the region surrounding the vaginal cavity during pre-treatment simulation and target localization, as well as during the delivery of radiation therapy to treat gynecological malignancy.